As a terminal device has an increasingly high demand on network traffic, an optical fiber transmission system has increasingly high requirements on a transmission bandwidth and a transmission rate. The optical fiber transmission system is a transmission system in which an optical fiber is used as a main transmission medium, and has features such as a high transmission speed and a long transmission distance.
An existing optical fiber transmission system usually includes a plurality of optical transceivers. Each optical transceiver includes an optical transmitter configured to transmit an optical signal and an optical receiver configured to receive an optical signal. A transmission rate of the existing optical fiber transmission system is usually 100 gigabits per second (Gbps). An increase in the transmission rate of the optical fiber transmission system is subject to technology development of the optical transceiver. For example, if the transmission rate of the optical fiber transmission system needs to be 400 Gbps, a sampling rate of a digital-to-analog converter (DAC) in the optical transmitter needs to be increased correspondingly. An existing DAC with a high sampling rate has excessively high costs. Consequently, an optical fiber transmission system with a high transmission rate is implemented at relatively high costs.